1. Field of the Invention
The invention relates in general to the field of semiconductor processing apparatus, and specifically to an improved Front Opening Unified Pod (FOUP).
2. Description of the Related Art
In the semiconductor manufacturing industry, a FOUP (Front Opening Unified Pod) is a container used to portably store a plurality of semiconductor wafers between processing steps. FOUPs are typically configured to be placed at an interface of a processing tool and are generally provided with a door configured to be automatically removed. Depending on a number of factors such as the size of a production run, cycle time, etc, wafers may sit in a FOUP for a substantial length of time between processing steps. During this time, it is possible for oxygen and moisture to leak into the FOUP. Unfortunately, moisture and oxygen have detrimental effects on the surfaces of semi-conductor wafers, and thus it is desirable to minimize the exposure of the wafers to these elements.
Moisture and oxygen levels can be reduced within an enclosed FOUP by introducing a purge gas (typically N2). Such FOUPs may have inlet and outlet ports in their bottom surface, as seen for example in U.S. Pat. No. 5,988,233 to Fosnight et al, particularly the disclosure regarding inlet and outlet ports is incorporated herein by reference and made part of the present disclosure. While purging delays or reduces oxidation and particle formation in the FOUP, there is a remaining need for a process for more quickly and efficiently reducing moisture and oxygen content within a FOUP to acceptable levels.